There is no problem with using fixed ads for Google Adsense, which are called sticky ads, but this is done with certain conditions and restrictions, which we mention below for horizontal fixed ads and vertical fixed ads. The following image is an example of the horizontal and vertical static ads used by the Seventh Day website.

Conditions for implementing sticky ads in Google Adsense
Publishers who choose to use static ads must adhere to the following implementation specifications. Vertical sticky ads are ad units that are vertical and stay on the sides of the page. Horizontal sticky ads are ad units in a horizontal format that persist at the top or bottom of the page.
Specifications of sticky ads
It should not be much more than the content.
It should be explained distinctly and differently from the content so that the visitor can easily distinguish the advertisement from the content. You should
write over it that it is an advertisement so that the visitor knows that it is an advertisement and not part of the content of the site.
It must not be adjacent to the content and also be far from the navigation buttons and ribbons. Scrolling
Sticky horizontal ad units are not allowed to float off window edges or follow your cursor.
These ads must not block part of the content

Sticky ads specifications
Shouldn’t be much more than content
to overwrite It’s an advertisement to let the visitor know It’s an advertisement and not part of the site’s content
Vertical static ads must not overlap with any other page content
The advertisement should never get too close to the content or site navigation functionality (including scrollbars)
Ads must scroll in and out of the viewport They cannot appear or disappear at any time in scrolling
Ads must only move in the vertical axis, with no horizontal scrolling Vertical static ad units are not allowed to float anywhere else on the page or follow the cursor
A static ad must remain in its fixed position on the screen without any stuttering, stuttering or visible delay while the user scrolls through the content .
Side ads in adsense
Finally, static ads may not be ideal for all types of websites, such as game pages or dynamically evolving pages. Publishers should confirm the previous conditions for consistent ad unit performance before implementing the unit across their sites. As always, the publisher must ensure that the user experience is of high quality and that the fixed ad unit does not disrupt or detract from the performance of the page.